Definition: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
Input: ['x', '6561', 'h', '1203', '3605', 't', 'l', 'i', 'i', 'c']

c, h, i, l, t, x